1. Field of the Invention
This invention relates to an improved apparatus having a light tight housing for making a predetermined enlargement of a graphic image. Specifically, the apparatus and method of the present invention utilizes a lens shroud having a fixed focal lengths lens and a gantry means for supporting a planar mat support wherein the lens and planar mat support are selectively differentially moveable relative to the predetermined location containing a graphic image so as to produce enlargements of a graphical image wherein the enlargement size is selected and determined by the position of a fixed focal length lens relative to the graphic image and the position of the planar mat support having a sensitized piece of photographic paper relative to the lens. This invention has application for use in a diffusion transfer photographic process wherein an exposed sensitized sheet of material can be developed and processed by use of the diffusion transfer technique to produce a developed large graphic image.
2. Disclosure of the Prior Art
Apparatus and method for producing an enlargement of a graphic image is well known in the art. One such apparatus and method is disclosed in U.S. Pat. No. 4,220,410 which is assigned to the same assignee as the present invention.
Other devices are well known in the art for producing selected enlargement of an image by controlling the position of a lens relative to the graphic image and the position of a light sensitive material relative to the lens.
The known prior devices specifically require that the lens be positioned in a selected location, that the print plane surface be positioned at a specific location and the exposure time is adjusted dependent on the relative position of the lens and the print plane relative to the graphic image.
Typically, the illuminating means for exposing the image onto the sensitized sheet is in the form of an incandescent lamp or other similar illumination source for producing the desired actinic radiation at a selected wavelength.
Other known enlargement apparatus are described in U.S. Pat. Nos. 450,475; 1,527,883; 1,994,091; 2,484,048; 3,540,807 and 3,322,029.
Each of the prior art devices utilize two mechanical changes, namely change of lens position or change of the sensitized material holder to control the size of enlargement, or if appropriate, reduction.